Scaffolding for the tanks of large tanker ships

ABSTRACT

Scaffolding for the construction, cleaning and repair of the interior of the tanks of large tanker ships consists of permanently emplaced wire netting secured to the sides of the tank.

United States Patent Otto Hanses P19 06 341.3and P17 81270.3

SCAFFOLDING FOR THE TANKS OF LARGE TANKER SHIPS References Cited UNITEDSTATES PATENTS 12/1935 Amesbury .1 9/195 3 Newland I [/1967 CathcartFOREIGN PATENTS 12/1964 France 4/1967 France Primary Examiner-ReinaldoP. Machado Attorney-Young & Thompson 17 Claims, 14 Drawing Figs.

182/128, 182/222, I 14/222 ABSTRACT: Scaffolding for the construction,cleaning and Int. Cl E04g 3/00 repair of the interior of the tanks oflarge tanker ships consists Field of Search 182/ I 38, of permanentlyemplaced wire netting secured to the sides of 139, 82,128, 222; 114/222,65 the tank.

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PATENTEUSEP 7m: 3,603,428

SHEEI 5 BF 7 In Ven for:

fifiAFFGlLDING FOR THE TANKS F LARGE TANKER SHIPS The present inventionrelates to scaffolding for the interior of the tanks of large tankerships, for supporting workmen during the construction, cleaning andrepair of the tanks. At present, during the construction of largetankers, it is customary to erect wooden scaffolding within the tanks asthe construction of the tans proceeds. When the ship is completed, thescaffolding is removed. But when the tanks are cleaned or repaired, thenit is necessary again to erect the scaffolding, and remove it when thecleaning or repair work is completed. A great deal of expensive labor isrequired to handle the scaffolding; and as the scaffolding is ordinarilywooden, its useful life is limited. It often happens that the erectionand removal of this scaffolding consumes the greater portion of the timethe ship is at the dock yard.

Accordingly, it is an object of the present invention to providescaffolding for the tanks of large tanker ships, which will requirerelatively little labor to emplace either initially or upon subsequentcleaning or repair operations.

Another object of the present invention is the provision of suchscaffolding which will provide a high degree of safety for the workers.

Finally, it is an object of the present invention to provide suchscaffolding which will be relatively simple and inexpensive tomanufacture and install, easy to utilize, maintain and repair, andrugged and durable in use.

Briefly, the present invention achieves these objects by providingscaffolding which can be erected at the time of construction of the tankand then left in place when the tanker is in use. For cleaning andrepair, therefore, when the tank is emptied, the scaffolding will beundamaged and in place.

To achieve this, the scaffolding is constructed by wire netting stripssupported by wire cables that are detachably secured to the walls of thetank. The netting is in a plurality of tiers, the upper one of whichwhich extends from side to side of the tank and the lower ones of whichextend only about the sides of the tank. The wire netting strips aresecured to each other, and the tiers below the upper tier have innerguard rails of the same material. Working platforms in the form ofcorrugated plates rest by gravity on the netting.

Other features, objects and advantages of the present invention willbecome apparent from a consideration of the following more detaileddescription, taken in connection with the accompanying drawings, inwhich:

FIG. 1 is a plan view ofa strip of wire netting for use in the uppertier of the scaffolding;

FIG. 2 is a view like FIG. 1, but showing the strips that are used atthe ends of the upper tier and also that form the lower tiers of wirenetting; FIG. 3 is a top plan view of the uppermost tier of wirenetting;

FIG. 4 is a somewhat schematic fragmentary perspective view of wirenetting according to the present invention, showing a working platformin place on the netting;

FIG. 5 is a perspective view of a work platform according to the presentinvention;

FIG. 6 is a schematic bottom plan view of one of the lower tiers ofscaffolding according to the present invention;

FIG. 7 is an enlarged fragmentary cross-sectional view taken on the lineVII-VII of FIG. 6;

FIG. 8 is a schematic enlarged fragmentary top plan view of a portion ofone of the lower tiers of scaffolding according to the presentinvention;

FIG. 9 is an enlarged plan view of one of the fastening members by whichthe ends of the support cables are secured to the walls of the tank;

FIG. 10 is an axial cross-sectional view of the structure of FIG. 9;

FIG. 11 is a cross-sectional view taken on the line XI-XI of FIG. 9;

FIG. 12 is a schematic fragmentary perspective view showing how accessmay be had between superposed tiers of the scaffolding;

FIG. 13 is a somewhat schematic fragmentary plan view showing anotherarrangement of work platforms on one of the lower tiers of scaffoldingof the present invention, and

FIG. 14 is a cross-sectional view of the structure shown in FIG. 8 orFIG. 13, showing one way of crossbracing the scaffolding.

Referring now to the drawings in greater detail, and first to theembodiment of FIG. 1, there is shown a strip of wire netting 10 which byitself may be conventional wire netting. Strip 10 is bounded by a frame12 consisting of a wire cable surrounding and secured to the strip.Sections 14 at the ends of the strip are more closely woven than in themidportions of the strip, and exhibit meshes 16 whose width is much lessthan that of meshes 18 in the central portion of the strip, preferablyby a ratio of 2:].

FIG. 2 shows a different embodiment of strip, for use by itself or incombination with strips as in FIG. 1. The FIG. 2 strip 20 comprises wirenetting having meshes 16' of the same width as meshes 16 of FIG. 1.

FIG. 3 shows the uppermost tier of scaffolding, in the form of a net Nwhich is of a size to stretch from side-to-side and from end-to-end ofthe uppermost portion of the tank in question. Net N is comprised of endstrips 20a and 20s as in FIG. 2, and intermediate strips 10,, 10 etc. asin FIG. 1. All the strips are arranged side by side and parallel to eachother with overlapping edges thereby to define a large central fieldcomprised by wide meshes l8 and a marginal area comprised by narrowmeshes l6 and 16. If desired, the entire net N can be of uniform meshwidth.

Cables 24 are interwoven between the overlapping edges of netting stripsto secure together the overlapping longitudinal edges of the individualstrips. As seen in FIG. 4, the ends of cables 24 are secured to thesidewalls of the tank by means of fastenings 26 whose structure will bedescribed in detail later On. The cables 12 that bound the individualstrips can also be secured to the tank walls in the same fashion.

In the direction perpendicular to cables 24, cables 22 are threadedthrough the net N adjacent and parallel to opposite longitudinal sidesthereof, on the inner sides of the sections 14 of small meshes 16.Cables 22 are secured to the tank walls at their ends by means offastenings 27, which are the same as fastenings 26 and whose structurewill be described later on.

As is also seen in FIG. 4, tensioning devices 13 are provided in cables12 from place to place thereabout, so as to impart the proper tension tothe net N.

The square fields 32 thus defined between cables 22 and 24 may forexample be two meters on a side and thus have an area of about foursquare meters.

Work platforms 30 are disposed on these square fields 32. The platforms30 are best seen in FIGS. 5 and 8. The platforms 30 are of corrugatedmetal characterized by downwardly extending depressions 38 at least oneof which has a downwardly extending bolt 36 thereon that is designed toextend through the wire netting and prevent lateral move ment of theplatform 30. Preferably, the platforms 30 are so disposed that the sidesof the bolts 36 bear laterally against a cable 22 or 24.

As will also be seen from FIG. 5, the platforms 30 are provided withslots 34 therethrough each of which terminates at one end at a bolt 36.The purpose of this construction is so that the platforms can be stackedand will nest with each other, laterally displaced from each other onlyby the width of a bolt 36, with a series of bolts extending through eachslot 34 in stairstep fashion. Of course, in use, the platforms will bearranged one by one on the netting and will not be stacked.

FIGS. 6-8 show one of the lower tiers of scaffolding of the presentinvention. In FIG. 6, the tier is shown roughly square, for use in atank whose cross section at that point is roughly square; so of coursethe FIG. 6 embodiment is not used with the FIG. 3 embodiment.

In FIG. 6, the walls of the tank are shown at 110, 112 and 112'. Thegallery 114 of wire netting consists of horizontal strips of wirenetting adjoining and secured to the tank walls, and upright wirenetting 115 along the inner margins of the gallery to provide railingsfor safety purposes. The netting 115 is integral with the horizontalwire netting of the gallery 114.

Gallery 114 is supported by wire cables 116, 116', 116", and 120, 120',120" attached to respective walls 110, 110 and 112, 112 and extendingacross the tank from wall to wall thereof. The ends of the cables aresecured to the sidewalls of the tank by fastenings 122 to be describedlater on.

Thus, in the illustrated embodiment, a wire cable 116 extends along thetank wall in the immediate vicinity thereof and a second wire cable 116"along the inner edge of the gallery. A third wire cable 116 is disposedalong the midline of the gallery parallel to and between the cables 116and 116". Two further wire cables 118 and 118 are provided above cable116" for the purpose of reinforcing the netting l 15 that forms theguard rail.

FIG. 8 also shows another possibility for the interconnection of twostrips endwise: a wire coil 124 is woven through overlapping end regionsof two strips of netting.

FIGS. 9, 10 and 11 show the fastenings for releasably securing the endsof the wire cables to the tank walls. A substantially U-shaped fastener122 is welded at its closed end to the tank wall and the two legs of thefastener 122 extend outwardly away from the tank wall. An inwardlyopening hollow keeper 128 is welded to the free ends of these legs andis characterized by an upwardly open slot 130 and an axial opening forthe reception of the cable 120. Each cable end has secured thereto asleeve 134 whose inner shoulder 132 abuts against keeper 128 when sleeve134 is fully seated in keeper 128. To insert and remove the cable end,the sleeve 134 must be sufficiently near the tank to clear the keeper128 entirely and to permit the cable 120 to be laid in the full lengthof slot 130, after which a pull on the cable will seat the sleeve 134 inthe keeper 128.

FIG. 12 shows a gangway produced through a gallery of the invention bybending apart overlapping edges 144, 146 of adjacent wire nettingstrips. A ladder can be inserted, while the edges 144 and 146 remainheld together fore and aft of the ladder by means of wire coil 148.

FIG. 13 shows that work platforms 150 can be somewhat differentlyarranged from platforms 30, with their corrugations extending lengthwiseof the gallery. Several of them can be arranged side-by-side, dependingon the width of the gallery. Each platform 150 has two pins 151projecting downwardly from the depressions of the corrugations, while aslot 152 adjoins each pin 151 to render the platforms nestable andstackable. FIGS. 13 and 14 also show an arrangement for increasing thestability of the scaffold. In order to avoid the necessity of stretchingwire cables across the middle of the tank space between the portions ofthe gallery on opposite sides of the tank, transverse supports 154 areinserted between cables 116 and 116'. In the illustrated embodiment, thesupports 154 are tubes of synthetic resin whose ends are in the form offorks 156 each of which embraces a wire cable to maintain the wirecables spaced against collapse toward each other when loaded. Of courseother forms of supports 154 may be adopted, and other forms of securingthem to the cables.

The cables and netting and plates of the present invention may be ofgalvanized iron but are preferably of steel coated with polyamide resinto render the steel resistant to sea water and oil.

From a consideration of the foregoing, therefore, it will be evidentthat all of the initially recited objects of the press invention havebeen achieved.

Although the present invention has been described and illustrated inconnection with preferred embodiments, it is to be understood thatmodifications and variations may be resorted to without departing fromthe scope of the invention, as those skilled in this art will readilyunderstand.

Having described my invention, 1 claim:

1. A tanker ship having a tank having upright tank walls, andscaffolding for the interior of the tank, comprising wire cablesattached at their ends to said walls, and horizontal wire netting stripssupported by and between the cables adjacent said walls.

2. Structure as claimed in claim 1, disposed adjacent the top of thetank and extending continuously from side-to-side and from end-to-end ofthe upper portion of the tank.

3. Structure as claimed in claim 1, disposed only adjacent the sidewallsof the tank, and a guard railing upstanding from only the inner edges ofthe scaffolding.

4. Structure as claimed in claim 3, said guard railing comprising wirenetting.

5. Structure as claimed in claim 4, and wire cables reinforcing saidguard railing.

6. Structure as claimed in claim 1, each said strip being bordered by awire cable, and means securing said cables to the walls of the tank.

7. Structure as claimed in claim 6, and tensioning devices for adjustingthe length of the wire cables that bound the netting strips.

8. Structure as claimed in claim 16, the longitudinal edges of saidstrips overlapping each other, and means interconnecting saidoverlapping edges of the strips.

9. Structure as claimed in claim 8, said interconnecting meanscomprising wire coils passing through said overlapping ed es.

%0. Structure as claimed in claim 16, at least some of said wire cablesbeing beneath portions of with said wire netting strips.

11. Structure as claimed in claim 10, and a platform resting on saidwire netting strips.

12. Structure as claimed in claim 1, said cables having enlarged ends,and fasteners secured to the walls of the tank for releasably receivingsaid enlarged cable ends, said fasteners comprising upwardly opendownwardly closed cradles aligned with said cables.

13. Structure as claimed in claim 1, and work platforms resting bygravity on said wire netting, each work platform having at least onedownwardly extending projection that extends through the wire netting torestrain lateral movement of the platform on the netting.

14. Structure as claimed in claim 13, each work platform having a slotextending from said projection and of a size to receive projections fromother work platforms thereby to render said work platforms stackable.

15. Structure as claimed in claim 1, whose material is steel coated withsynthetic resin.

16. Structure as claimed in claim 1, and support means holding apart apair of parallel cables against the tendencyof the cables to move towardeach other under load.

17. Structure as claimed in claim 1, and a plurality of con nectorsspaced along a said tank wall along which the scaffolding extends andinterconnecting the scaffolding with the wall and extendingperpendicular to the wall.

1. A tanker ship having a tank having upright tank walls, andscaffolding for the interior of the tank, comprising wire cablesattached at their ends to said walls, and horizontal wire netting stripssupported by and between the cables adjacent said walls.
 2. Structure asclaimed in claim 1, disposed adjacent the top of the tank and extendingcontinuously from side-to-side and from end-to-end of the upper portionof the tank.
 3. Structure as claimed in claim 1, disposed only adjacentthe sidewalls of the tank, and a guard railing upstanding from only theinner edges of the scaffolding.
 4. Structure as claimed in claim 3, saidguard railing comprising wire netting.
 5. Structure as claimed in claim4, and wire cables reinforcing said guard railing.
 6. Structure asclaimed in claim 1, each said strip being bordered by a wire cable, andmeans securing said cables to the walls of the tank.
 7. Structure asclaimed in claim 6, and tensioning devices for adjusting the length ofthe wire cables that bound the netting strips.
 8. Structure as claimedin claim 16, the longitudinal edges of said strips overlapping eachother, and means interconnecting said overlapping edges of the strips.9. Structure as claimed in claim 8, said interconnecting meanscomprising wire coils passing through said overlapping edges. 10.Structure as claimed in claim 16, at least some of said wire cablesbeing beneath portions of with said wire netting strips.
 11. Structureas claimed in claim 10, and a platform resting on said wire nettingstrips.
 12. Structure as claimed in claim 1, said cables having enlargedends, and fasteners secured to the walls of the tank for releasablyreceiving said enlarged cable ends, said fasteners comprising upwardlyopen downwardly closed cradles aligned with said cables.
 13. Structureas claimed in claim 1, and work platforms resting by gravity on saidwire netting, each work platform having at least one downwardlyextending projection that extends through the wire netting to restrainlateral movement of the platform on the netting.
 14. Structure asclaimed in claim 13, each work platform having a slot extending fromsaid projection and of a size to receive projections from other workplatforms thereby to render said work platforms stackable.
 15. Structureas claimed in claim 1, whose material is steel coated with syntheticresin.
 16. Structure as claimed in claim 1, and support means holdingapart a pair of parallel cables against the tendency of the cables tomove toward each other under load.
 17. Structure as claimed in claim 1,and a plurality of connectors spaced along a said tank wall along whichthe scaffolding extends and interconnecting the scaffolding with thewall and extending perpendicular to the wall.